The present invention relates to a device for the reception and/or the transmission of multibeam signals which are useable more especially in the field of wireless transmissions.
In the known systems for high-throughput wireless transmissions useable in particular in a domestic environment, the signals sent by the transmitter reach the receiver along a plurality of distinct paths. This results at the level of the receiver in interference liable to cause fadeouts and distortions of the signal transmitted and consequently a loss or a degradation of the information to be transmitted. To remedy this drawback, directional antennas of the horn, reflector or array type are usually used, these antennas being used at the transmitting and/or receiving end and making it possible to combat or attenuate the degradations related to multipaths. Specifically, in addition to the gain afforded by the directional antenna, the latter makes it possible by spatial filtering, on the one hand to reduce the number of multipaths, and hence to reduce the number of fadeouts, and on the other hand to reduce the interference with other systems operating in the same frequency band.
Since directional antennas do not allow for significant azimuthal spatial coverage, French Patent Application No. 98 13855 filed in the name of the applicant has therefore proposed a compact antenna making it possible to increase the spectral efficiency of the array by reusing the frequencies by virtue of a segmentation of the physical space to be covered by the radiation pattern of the sectorial antenna. The antenna proposed in the above patent application consists of a coplanar circular arrangement about a central point of Vivaldi-type printed radiating elements making it possible to present several directional beams sequentially over time, the set of beams giving complete 360° coverage of space.
Whereas this type of antenna makes it possible to obtain good operation of the receiving device, it is often advantageous in transmission to be able to obtain omnidirectional coverage of space, for example when the transmitter system must be able to declare itself to all the users or transmit to several receivers.
The aim of the present invention is therefore to propose a device for the reception or the transmission of multibeam signals making it possible to meet this need.